Why do we salivate when we're nauseous?

Whether you’re a victim of illness or boozy overindulgence, a suddenly watery mouth – atop of a queasy stomach – is never a sign of good things to come.

When the drool pools, you know what’s up: your stomach contents. Literally. It’s not going to look pretty. And afterward, you’re not going to feel pretty.

But salivating before vomiting runs counter to our basic understanding of slobber. Shouldn’t that oral reaction only accompany the scent, sight, promise or actual consumption of tasty morsels?

Actually, it’s all part of the same digestive chain reaction – a chemical concoction involving your mouth and your gastric juices, the fluid generated within your gut to help your body dissolve chewed food.

“The body is attempting to solve the problem of whatever is causing the nausea and (in a sense) digest it,” said Dr. Isaac Eliaz, who blends Western medicine with acupuncture and traditional Chinese medicine – an approach known as “integrative medicine.”

“Our digestive process starts in the mouth with the saliva, which is high in amylase, an important digestive enzyme that helps break down carbohydrates. So as part of the digestive process triggered by whatever may be causing the nausea, we have increased salivation,” said Eliaz, based in Sebastopol, Calif.

At the same time, nausea stimulates the vagus nerve – which runs from the brain down through the neck, relaying information about the condition of body’s organs, Eliaz said. An upset stomach also awakens the parasympathetic nervous system, which revs and runs your “rest and digest” functions, including crying and urination plus, in this case, digestion and salivation.

In short, that extra drool means your stomach and brain are chatting up a storm as you just try to hang on through that bumpy night, or that rough morning.

But we’re not here to simply explain this weird sensation. We seek to provide a tip to, perhaps, prevent you from hurling.

Check out the wisdom offered by Ken Beckstead, 48, a Las Vegas resident: “Whenever I start to salivate excessively and feel like I am going to vomit, I start spitting the excess saliva.

“Swallowing the saliva actually makes you vomit. Spitting it out until the saliva stops filling your mouth will help you not vomit,” Beckstead said.

Doctor?

“I can say that there is, indeed, an explanation to such relief,” Eliaz said. That reason, he adds, comes via his knowledge of traditional Chinese medicine.

“It is specific to a certain energetic pattern or issue that will cause nausea: what we call in traditional Chinese medicine the accumulation of phlegm and mucus in the stomach,” Eliaz said. “In this case, spitting saliva will help relieve the condition.”

So, East or West, the solution: spit and rest. Either way, though, you'll probably need a bucket.